1 All lenses have __________.A) no curves at all B) only one curved side C) at least one curved side D) two curved sides 2 What type of lenses do microscopes use?A) convex B) reflecting C) plane D) concave 3 What is a focal length?A) the difference between the angle of incidence and the angle of reflection B) the distance from the center of the mirror to the focal point C) the distance from the mirror to the reflecting object D) the distance light travels along a reflective surface 4 What causes light waves to refract?A) The speed of light is reduced to zero. B) The speed of light changes from one medium to the next. C) The speed of light remains constant. D) The light is repelled by some materials. 5 To correct nearsightedness, which lenses should be used?A) convex B) plane C) reflecting D) concave 6 Which is an example of a convex lens?A) a car windshield B) magnifying glass C) a side mirror on a car D) nearsighted eyeglasses 7 A source of light emits light rays __________.A) only at right angles B) in a circle C) in all directions D) in a straight line 8 Object A reflects more than object B. Therefore, object A is __________ object B.A) just as smooth as B) made of the same material as C) rougher than D) smoother than 9 A mirror with a flat surface is called a __________ mirror.A) flat B) convex C) plane D) concave 10 What are the primary pigment colors?A) red, blue, and yellow B) yellow, magenta, and cyan C) black and white D) red, orange, yellow, green, blue, indigo, and violet 11 What is the main purpose of a telescope?A) to gather as much light as possible B) to reflect light at an object C) to make objects appear closer D) to magnify an image 12 A blue car looks blue because __________.A) blue light is reflected while others are absorbed B) the blue car emits blue light C) blue light is absorbed while others are reflected D) the blue car is opaque 13 Why can you see most objects?A) light refracts through them B) light reflects off them C) they emit light D) they absorb light 14 What happens to an image when the focal length of a lens is reduced?A) It gets larger. B) It gets smaller. C) It goes out of focus. D) It remains the same. 15 Where does an image form on the eye?A) the optic nerve B) the lens C) the cornea D) the retina 16 The image formed by a concave lens is similar to that formed by a __________.A) convex lens B) concave mirror C) convex mirror D) plane mirror 17 The speed of light is __________.A) faster in water than in air B) slower in water than in air C) the same speed in water and air D) fastest in water 18 Which of the following is the law of reflection?A) The angle of incidence is equal to the normal. B) The normal is perpendicular to the reflecting surface. C) The angle of reflection is equal to the normal. D) The angle of incidence is equal to the angle of reflection. 19 Large telescopes magnify with what?A) mirrors B) cameras C) lenses D) computers 20 Which is not a primary color?A) yellow B) green C) red D) blue